Carbon black is produced by the incomplete combustion of a hydrocarbon such as petroleum, natural gas and other well-known materials at high temperatures. When separated from the reaction gases, the product is a fluffy, carbon black powder.
Carbon black can be produced using a modular or staged process such as for example the type disclosed and claimed in U.S. Pat. No. Re. 28,974. A staged process is comprised of a primary (first-stage) combustion zone wherein a stream of hot gaseous combustion products is formed; a second or transition zone wherein a liquid hydrocarbon feedstock either in pre-atomized form, or in the form of non-preatomized coherent streams, is injected substantially radially from the outer or inner periphery of the combustion gas stream into the pre-formed stream of hot combustion gases; and a third zone (the reaction zone) wherein the carbon black formation occurs prior to termination of the reaction by quenching.
There are instances, however, where it is desired to produce carbon blacks which for a given surface area are characterized by having lower tinting strength and higher structure. The blacks are useful in preparing rubber compounds having increased modulus and rebound values.
Accordingly, the primary object of the invention is to provide a novel and improved process for preparing carbon blacks which for a given surface area are characterized by having lower tinting strength and higher structure.
Other and different objects, advantages and features of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description and claims.